Impact of Sampling Jitter on Mostly-Digital Architectures for UWB Bio-Medical Applications

• Main Authors: Fort, A., Chen, M., Brodersen, R.W., Desset, C., Wambacq, P., Van Biesen, L.
• Format: Conference Proceeding
• Language: English
• Subjects: Analytical models; Biomedical communication; Biomedical signal processing; Bit error rate; Circuit synthesis; Digital signal processing; Jitter; Sampling methods; Signal sampling; Ultra wideband technology
• ISSN: 1550-3607; 1938-1883
• DOI: 10.1109/ICC.2007.956

Ultra-wideband (UWB) impulse radio is a promising technique for low-power bio-medical communication systems. While a range of analog and digital UWB architectures exist, the mostly-digital approach without analog down-conversion enables better technology scaling and signal processing flexibility. Furthermore, recently proposed sub-sampling schemes and advances in high-speed ADC circuit design are helping to make this approach more feasible at low power. However, architectures that directly sample the received signal are more vulnerable to sampling jitter. Currently, there does not exist a model describing the impact of sampling jitter making it difficult to determine appropriate tolerances or to establish the feasibility of digital architectures. To address this problem, we have developed a model of sampling jitter and derived a generic bit error rate expressions for a digital UWB modem with sampling jitter, additive noise, and imperfect channel estimation in a generic multipath environment. We then use this model to investigate the performance of sub-sampled digital UWB in a body area network. This paper explains this analytical model and compares it with simulations results for communication around the body.